Putting Food By - Janet Greene [18]
Syrup holding bath is simply dropping each piece of cut fruit into the syrup it will be canned or frozen in, and to which you may have added ascorbic acid. Fruit held this way before canning is usually packed Hot (precooked); if Raw pack, the fruit must be fished out, put in the containers, and covered with the syrup after it has been brought to boiling.
Sulfuring before drying can be used with most fruits in order to slow enzymatic action. All fruits and berries (except grapes) that are to be dried in open-air/sun are sometimes exposed to sulfur dioxide (SO2), which is the fumes from burning pure sulfur.
Get “sublimed” sulfur (also called “sulfur powder”) from a drugstore, a health and beauty store, or a chemical-supply house on the internet. It’s pure, is a soft-yellow powder, and 2 ounces will sulfur 16 to 18 pounds of prepared fruit. Chapter 21 tells how to burn it. (Don’t use fumigating compounds even though they contain some sulfur.)
Note: sulfites in solution have been banned for use on displays of produce for sale, and on “salad bar” offerings.
Specifically for Vegetables
Blanching is used before freezing or drying all vegetables (except for sliced onions or sweet green bell peppers) in order to slow down enzymatic action and produce the side-effect of helping to protect natural color and some texture. Blanching may be done in boiling water, in steam, or in a microwave oven (as in treating fruits, earlier). Specific times are given in instructions for individual foods later.
Before canning, white potatoes are held in a mild salt solution; salsify (oyster plant) is held in the mild acid-brine bath we mentioned earlier for certain cut fruits.
Specifically for Meats: The Nitrates/Nitrites
Potassium nitrate and sodium nitrate have been called saltpeter for generations, and for even longer have been used in the salt-curing of meats. Most simply, nitrates are changed into nitrites by metabolism when we eat them, or by the action with the protein of raw meat being cured. The nitrites, in turn, help to make nitrosamines—and these latter substances have been found to cause cancer in laboratory animals. It is this fear of carcinogens in human beings that has caused a continuing controversy about the use of nitrites in preservation of food, and they are under scrutiny by the FDA and the USDA.
Meanwhile it has been established that nitrites do help prevent the formation of the dreaded C. botulinum toxin—aside from stabilizing the appetizing pink color of ham, cured meats, frankfurters, etc., that may or may not be smoked following their cure in salt and nitrates/nitrites. Because they are considered able to help reduce the possibility of botulism poisoning, nitrites currently are tolerated in small amounts by food scientists. Nitrates can mask food spoilage, so read labels for expiration dates.
The answer to their use is continued vigilance and restriction to minimum proportions in commercially prepared foods. It is important not to add more nitrates/nitrites than are given in the recipes in Chapter 20 or to increase the amounts of commercially prepared cures containing these substances and which are sold in hardware and farm supply stores, in some supermarkets, and in many online stores.
It is interesting that most Americans ingest at least as much nitrite-forming substances in leafy and green vegetables and other highly approved foods as they get in the cured meats.
Ascorbic acid. Good old Vitamin C again. It will hold the color of cured meat—not so brightly and certainly more briefly than saltpeter does. It will not prevent botulism. Use ¼ teaspoon pure crystalline ascorbic acid for every 5 pounds of dressed meat to be cured; add it to the salt mixture or to the brine.
Specifically for Seafood
Citric acid (and lemon juice) can be used for canning: the picked meat of crabs, lobsters, shrimp, and clams is given a brief dunk in a fairly tart solution of citric acid or lemon juice as a way to offset the darkening action of minerals naturally present in such foods (otherwise the meats would be likely to discolor